Ante rem Structuralism and the Myth of Identity Criteria

This thesis examines the connections between the motivations of ante rem structuralism and the problem of automorphism. Ante rem structuralists are led to the problem of automorphism because of their commitment to the thesis of structure-relative identity. Ladyman's and Button's solutions to the problem are both unsatisfactory. The problem can be solved only if ante rem structuralists drop the thesis of structure-relative identity. Besides blocking the problem of automorphism, there are further reasons why the thesis has to be dropped. (i) The purported metaphysical and epistemic purchase of adopting the thesis can be put into doubt. (ii) Primitive identity within a mathematical structure is more in line with ante rem structuralist's commitment to the faithfulness constraint and to the ontological priority of structure over positions. However, the cost of dropping the thesis is that ante rem structuralists cannot provide a satisfactory solution to Benacerraf's problem of multiple reductions of arithmetic

Intuitionism and logical revision.

The topic of this thesis is logical revision: should we revise the canons of classical reasoning in favour of a weaker logic, such as intuitionistic logic? In the first part of the thesis, I consider two metaphysical arguments against the classical Law of Excluded Middle-arguments whose main premise is the metaphysical claim that truth is knowable. I argue that the first argument, the Basic Revisionary Argument, validates a parallel argument for a conclusion that is unwelcome to classicists and intuitionists alike: that the dual of the Law of Excluded Middle, the Law of Non-Contradiction, is either unknown, or both known and not known to be true. As for the second argument, the Paradox of Knowability, I offer new reasons for thinking that adopting intuitionistic logic does not go to the heart of the matter. In the second part of the thesis, I motivate an inferentialist framework for assessing competing logics-one on which the meaning of the logical vocabulary is determined by the rules for its correct use. I defend the inferentialist account of understanding from the contention that it is inadequate in principle, and I offer reasons for thinking that the inferentialist approach to logic can help model theorists and proof-theorists alike justify their logical choices. I then scrutinize the main meaning-theoretic principles on which the inferentialist approach to logic rests: the requirements of harmony and separability. I show that these principles are motivated by the assumption that inference rules are complete, and that the kind of completeness that is necessary for imposing separability is strictly stronger than the completeness needed for requiring harmony. This allows me to reconcile the inferentialist assumption that inference rules are complete with the inherent incompleteness of higher-order logics-an apparent tension that has sometimes been thought to undermine the entire inferentialist project. I finally turn to the question whether the inferentialist framework is inhospitable in principle to classical logical principles. I compare three different regimentations of classical logic: two old, the multiple-conclusions and the bilateralist ones, and one new. Each of them satisfies the requirements of harmony and separability, but each of them also invokes structural principles that are not accepted by the intuitionist logician. I offer reasons for dismissing multiple-conclusions and bilateralist formalizations of logic, and I argue that we can nevertheless be in harmony with classical logic, if we are prepared to adopt classical rules for disjunction, and if we are willing to treat absurdity as a logical punctuation sign

Metaontological Studies relating to the Problem of Universals

My dissertation deals with metaontology or metametaphysics. This is the subdiscipline of philosophy that is concerned with the investigation of metaphysical concepts, statements, theories and problems on the metalevel. It analyses the meaning of metaphysical statements and theories and discusses how they are to be justified. The name "metaontology" is recently coined, but the task of metaontology is the same as Immanuel Kant already dealt with in his Critique of Pure Reason. As methods I use both historical research and logical (or rather semantical) analysis. In order to understand clearly what metaphysical terms or theories mean or should mean we must both look at how they have been characterized in the course of the history of philosophy and then analyse the meanings that have historically been given to them with the methods of modern formal semantics. Metaontological research would be worthless if it could not in the end be applied to solving some substantive ontological questions. In the end of my dissertation, therefore, I give arguments for a solution to the substantively ontological problem of universals, a form of realism about universals called promiscuous realism. To prepare the way for that argument, I argue that the metaontological considerations most relevant to the problem of universals are considerations concerning ontological commitment, as the American philosophers Quine and van Inwagen have argued, not those concerning truthmakers as such philosophers as the Australian realist D. M. Armstrong have argued or those concerning verification conditions as such philosophers as Michael Dummett have argued. To justify this conclusion, I go first through well-known objections to verificationism, and show that they apply also to current verificationist theories such as Dummett's theory and Field's deflationist theory of truth. In the process I also respond to opponents of metaphysics who try to show with the aid of verificationism or structuralism that metaphysical questions would be meaningless or illegitimate in some other way. Having justified the central role of ontological commitment, I try to develop a detailed theory of it. The core of my work is a rigorous formal development of a theory of ontological commitment. I construct it by combining Alonzo Church's theory of ontological commitment with Tarski's theory of truth.Väitöskirjani käsittelee metaontologiaa eli metametafysiikkaa. Tämä on se metafilosofian osa-alue, joka tutkii metafyysisten väitteiden ja termien merkitystä ja sitä, miten metafyysiset väitteet ja teoriat voitaisiin oikeuttaa. Metafysiikka tai ontologia on taas tiede, joka tutkii olevaa yleensä tai kaikkeutta kokonaisuutena. Menetelminä käytän sekä historiallista tutkimusta että loogista (tai pikemminkin semanttista) analyysiä. On olemassa kolme pääasiallista teoriaa siitä, mikä on metaontologian keskeisin käsite. Sellaiset filosofit kuin australialainen Armstrong ovat väittäneet, että se on totuustekijöiden (truthmakers) käsite. Sellaiset anti-realistiset filosofit kuin englantilainen filosofi Michael Dummett ovat taas väittäneet että se on todennettavuusehtojen (verification conditions) käsite. Argumentoin näitä kahta käsitystä vastaan ja kolmannen puolesta, jonka mukaan keskeisin käsite on ontologisten sitoumusten käsite, kuten amerikkalainen filosofi Quine on väittänyt. Argumentoin, että Quinen ontologisten sitoumusten teoria voidaan erottaa hänen muista ontologisista näkemyksistään, kuten hänen semanttisesta holismistaan, ontologisesta relativismistaan tai strukturalismistaan, mitkä ovat mielestäni virheellisiä. Väitöskirjani ydin on täsmällinen teoria ontologisista sitoumuksista, jonka rakennan yhdistämällä Alonzo Churchin teoriaa ontologisista sitoumuksista Alfred Tarskin totuusteoriaan. Metaontologinen tutkimus olisi arvotonta, ellei sitä voisi lopulta käyttää substantiivisten ontologisten kysymysten ratkaisemiseen. Käsittelen siksi väitöskirjani loppupuolella yhtä perinteistä ontologian ongelmaa, universaalien ongelmaa. Jo Aristoteles määritteli teoksessaan Tulkinnasta universaalien olevan olioita, jotka (Lauri Carlsonin käännöksen mukaan) luonnostaan predikoidaan (sanotaan) monesta. Universaaliongelma koskee sitä, ovatko tällaiset universaalit vain kielellisiä ilmauksia, kuten yleisnimet, verbit ja adjektiivit, tai ihmismielestä riippuvia olioita, kuten yleiskäsitteet, vai voidaanko myös sanoa, että maailmassa itsessään olevia olioita voidaan predikoida jostakin. Realistin mukaan vastaus on myöntävä. Esitän väitöskirjan lopussa alustavan argumentin universaaleja koskevan realismin puolesta

On modal-epistemic variants of Shapiro's system of Epistemic Arithmetic

This paper presents formalizations of classical first-order arithmetic which contain a modal and an epistemic operator. The embedding under variants of GodeΓs translation of Intuitionistic arithmetic in such systems is discussed, and for one modal-epistemic system of arithmetic a possible worlds semantics is given.publishe

Fourth Conference on Artificial Intelligence for Space Applications

Proceedings of a conference held in Huntsville, Alabama, on November 15-16, 1988. The Fourth Conference on Artificial Intelligence for Space Applications brings together diverse technical and scientific work in order to help those who employ AI methods in space applications to identify common goals and to address issues of general interest in the AI community. Topics include the following: space applications of expert systems in fault diagnostics, in telemetry monitoring and data collection, in design and systems integration; and in planning and scheduling; knowledge representation, capture, verification, and management; robotics and vision; adaptive learning; and automatic programming

Dual processes in mathematics: reasoning about conditionals

This thesis studies the reasoning behaviour of successful mathematicians. It is based on the philosophy that, if the goal of an advanced education in mathematics is to develop talented mathematicians, it is important to have a thorough understanding of their reasoning behaviour. In particular, one needs to know the processes which mathematicians use to accomplish mathematical tasks. However, Rav (1999) has noted that there is currently no adequate theory of the role that logic plays in informal mathematical reasoning. The goal of this thesis is to begin to answer this specific criticism of the literature by developing a model of how conditional “if…then” statements are evaluated by successful mathematics students. Two stages of empirical work are reported. In the first the various theories of reasoning are empirically evaluated to see how they account for mathematicians’ responses to the Wason Selection Task, an apparently straightforward logic problem (Wason, 1968). Mathematics undergraduates are shown to have a different range of responses to the task than the general well-educated population. This finding is followed up by an eve-tracker inspection time experiment which measured which parts of the task participants attended to. It is argued that Evans’s (1984, 1989, 1996, 2006) heuristic-analytic theory provides the best account of these data. In the second stage of empirical work an in-depth qualitative interview study is reported. Mathematics research students were asked to evaluate and prove (or disprove) a series of conjectures in a realistic mathematical context. It is argued that preconscious heuristics play an important role in determining where participants allocate their attention whilst working with mathematical conditionals. Participants’ arguments are modelled using Toulmin’s (1958) argumentation scheme, and it is suggested that to accurately account for their reasoning it is necessary to use Toulmin’s full scheme, contrary to the practice of earlier researchers. The importance of recognising that arguments may sometimes only reduce uncertainty in the conditional statement’s truth/falsity, rather than remove uncertainty, is emphasised. In the final section of the thesis, these two stages are brought together. A model is developed which attempts to account for how mathematicians evaluate conditional statements. The model proposes that when encountering a mathematical conditional “if P then Q”, the mathematician hypothetically adds P to their stock of knowledge and looks for a warrant with which to conclude Q. The level of belief that the reasoner has in the conditional statement is given by a modal qualifier which they are prepared to pair with their warrant. It is argued that this level of belief is fixed by conducting a modified version of the so-called Ramsey Test (Evans & Over, 2004). Finally the differences between the proposed model and both formal logic and everyday reasoning are discussed

Dual processes in mathematics : reasoning about conditionals

This thesis studies the reasoning behaviour of successful mathematicians. It is based on the philosophy that, if the goal of an advanced education in mathematics is to develop talented mathematicians, it is important to have a thorough understanding of their reasoning behaviour. In particular, one needs to know the processes which mathematicians use to accomplish mathematical tasks. However, Rav (1999) has noted that there is currently no adequate theory of the role that logic plays in informal mathematical reasoning. The goal of this thesis is to begin to answer this specific criticism of the literature by developing a model of how conditional “if…then” statements are evaluated by successful mathematics students. Two stages of empirical work are reported. In the first the various theories of reasoning are empirically evaluated to see how they account for mathematicians’ responses to the Wason Selection Task, an apparently straightforward logic problem (Wason, 1968). Mathematics undergraduates are shown to have a different range of responses to the task than the general well-educated population. This finding is followed up by an eve-tracker inspection time experiment which measured which parts of the task participants attended to. It is argued that Evans’s (1984, 1989, 1996, 2006) heuristic-analytic theory provides the best account of these data. In the second stage of empirical work an in-depth qualitative interview study is reported. Mathematics research students were asked to evaluate and prove (or disprove) a series of conjectures in a realistic mathematical context. It is argued that preconscious heuristics play an important role in determining where participants allocate their attention whilst working with mathematical conditionals. Participants’ arguments are modelled using Toulmin’s (1958) argumentation scheme, and it is suggested that to accurately account for their reasoning it is necessary to use Toulmin’s full scheme, contrary to the practice of earlier researchers. The importance of recognising that arguments may sometimes only reduce uncertainty in the conditional statement’s truth/falsity, rather than remove uncertainty, is emphasised. In the final section of the thesis, these two stages are brought together. A model is developed which attempts to account for how mathematicians evaluate conditional statements. The model proposes that when encountering a mathematical conditional “if P then Q”, the mathematician hypothetically adds P to their stock of knowledge and looks for a warrant with which to conclude Q. The level of belief that the reasoner has in the conditional statement is given by a modal qualifier which they are prepared to pair with their warrant. It is argued that this level of belief is fixed by conducting a modified version of the so-called Ramsey Test (Evans ;Over, 2004). Finally the differences between the proposed model and both formal logic and everyday reasoning are discussed.EThOS - Electronic Theses Online ServiceEconomic and Social Research Council (Great Britain) (ESRC)GBUnited Kingdo

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp